Add SK-AM68 and SK-AM69 board support

[3V3RYONE]

Description

This PR adds support for the Texas Instruments SK-AM68 and SK-AM69 boards.

Notable features of SK-AM68 board:

• 16GB LPDDR4‐4266 with support for inline error correction code (ECC)
• DisplayPort 4K resolution with MST support and HDMI
• Two CSI-2 ports compatible with Raspberry Pi
• 8 TOPS deep-learning performance and hardware-accelerated edge AI
• Three USB 3.0 Type A ports, one USB 3.0 Type C port
• Gigabit Ethernet and 4x CAN-FD Headers
• One M.2 key M connector

Notable features of SK-AM69 board:

• 32GB LPDDR4‐4266 with support for inline error correction code (ECC)
• DisplayPort 4K resolution with MST support and HDMI
• Three CSI-2 ports compatible with Raspberry Pi
• 32 TOPS deep-learning performance and hardware-accelerated edge AI
• Three USB 3.0 Type A ports, one USB 3.0 Type C port
• Gigabit Ethernet and 4x CAN-FD Headers
• One M.2 key E connector and one M.2 key M connector

Further details like features, schematics and purchase links can be found on the board page: SK-AM68 SK-AM69

Note: To support SK-AM69 board, we had to switch U-Boot source for K3 family devices to ti-u-boot:2023.04 (commit 1), since boot configs for SK-AM69 board has not been upstreamed yet.

How Has This Been Tested?

First, we verified that the changes introduced do not deprecate any existing board support by:

• [ ] Build and boot SK-AM62B Jammy CLI/Standard on Edge(v6.6) kernel
• [ ] Build and boot SK-AM64B Jammy CLI/Standard on Current(v6.1) and Edge(v6.6) kernels
• [ ] Build and boot SK-TDA4VM Jammy CLI/Standard on Current(v6.1) and Edge(v6.6) kernels

Further, the functionalities of new boards were tested by:

• [ ] Build and boot SK-AM68 Jammy CLI/Standard on Current(v6.1) and Edge(v6.6) kernels
• [ ] Build and boot SK-AM69 Jammy CLI/Standard on Current(v6.1) and Edge(v6.6) kernels
• [ ] Gbit Ethernet works
• [ ] USB 3.0 ports work

Checklist:

• [ ] My code follows the style guidelines of this project
• [ ] I have performed a self-review of my own code
• [ ] I have commented my code, particularly in hard-to-understand areas
• [ ] I have made corresponding changes to the documentation
• [ ] My changes generate no new warnings
• [ ] Any dependent changes have been merged and published in downstream modules

[EvilOlaf]

Why is it necessary to change the whole u-boot source? Necessary patches for mainline u-boot (which could be tagged to a specific release) can be added here: https://github.com/armbian/build/tree/main/patch/u-boot

[3V3RYONE]

Update: Applied patches required for SK-AM69 board on upstream U-Boot source. Build is successful, but there are problems (device specific) while booting. Currently debugging that, will push a commit once things are okay.

[glneo]

If SK-AM69 is not yet ready, let's split out that board from this PR and start with just SK-AM68.

[3V3RYONE]

Updated this PR to add support for SK-AM68 board only.

[igorpecovnik]

Updated this PR to add support for SK-AM68 board only.

Perhaps also update description of this PR.

If @glneo is happy, I am.

[glneo]

Looks good to me, thanks for this new platform @3V3RYONE :)

[HeyMeco]

@3V3RYONE

Update: Applied patches required for SK-AM69 board on upstream U-Boot source. Build is successful, but there are problems (device specific) while booting. Currently debugging that, will push a commit once things are okay.

any update regarding SK-AM69?

[3V3RYONE]

@3V3RYONE

Update: Applied patches required for SK-AM69 board on upstream U-Boot source. Build is successful, but there are problems (device specific) while booting. Currently debugging that, will push a commit once things are okay.

any update regarding SK-AM69?

SK-AM69 boot support has been merged to Upstream U-Boot next. Once it comes under a tagged release, we will add support for it here.